The next Bundesliga season saw the technically gifted player playing his first games,[2] being a starter in the European Cup final defeat of his side against Nottingham Forest at the Santiago Bernabéu Stadium on 28 May 1980.

[3] He was back as a regular in the line-ups of Hamburg manager Ernst Happel after his career had, for some time, been called to a halt due to his club signing veteran German legend Franz Beckenbauer in November 1980.

The most tragic moment of his playing days, however, happened on 31 March 1984, in the Bundesliga tie against SV Waldhof Mannheim.

At the time he finally abandoned the hope of recovery, merely 26 years of age, the talented sweeper had played in 121 Bundesliga matches (seven goals) for Hamburger SV.

Leaving these jobs aside, Hieronymus enjoyed a return to Hamburger SV in 1997 as the new marketing manager of Die Rothosen.